Alcoholated basic aluminum halide compounds and method of making same

ABSTRACT

Anhydrous basic aluminum halide complexes may be formed from hydrated or partially hydrated aluminum halides by substituting alcohol for the free and coordinated water in the hydrated compound. The anhydrous alcoholated complexes are produced by dissolving the hydrated compound in alcohol, adding dimethoxypropane (DMP) or diethoxypropane (DEP) to the solution, heating and concentrating the solution, adding additional DMP, DEP or other precipitating agent to precipitate out the alcoholated complex, and drying the precipitate. The products may be useful in antiperspirant compositions and as intermediates in non-aqueous solvents.

United States Gilman et al.

[15] 3,692,! 1 [451 Sept. 19,1972

[ ALCOHOLATED BASIC ALU NUM HALIDE COMPOUNDS AND METHOD OF MAKING SAME[72] Inventors: William S. Gilman, South Plainfield;

John Jones, North Plainfield; Andrew M. Rubino, New Providence,

21 Appl. No.: 84,172

[52] US. Cl. ..260/448 R, 252/86, 260/999 [51] Int. Cl. ..C07f 5/06 [58]Field of Search ..260/448 R, 448 AD [56] References Cited UNITED STATESPATENTS 2,823,144 2/1958 Dalton ..260/448 AD X 3,472,928 10/1969 Virzi..424/68 3,523,129 8/1970 l-lolbert et a1. ..260/448 AD 3,359,16912/1967 Slater et a1. ..260/448 AD 3,51 1,864 5/1970 Ugelow et a1...260/448 AD 2,953,479 9/1960 Heyden et al. .....260/448 R X 3,420,9321/1969 Jones et a1 ..260/448 AD X 3,472,929 10/1969 Jones et al..260/448 AD X 3,523,130 8/1970 Jones et a1. ..260/448 AD OTHERPUBLICATIONS Academy of Athens Record of Proceedings Vol. 6 (1931) pp.148- 153 (translation) Primary Examiner-Tobias E. Levow AssistantExaminer-H. M. S. Sneed Attorney-Carl C. Batz [57] ABS ACT Anhydrousbasic aluminum halide complexes may be formed from hydrated or partiallyhydrated aluminum halides by substituting alcohol for the free andComdinated water in the hylrated compound. The anhydrous alcoholatedcomplexes are produced by dissolving the hydrated compound in alcohol,adding dimethoxypropane-(DMP) or diethoxypropane (DEP) to the solution,heating and concentrating the solution, adding additional DMP, DEP orother precipitating agent to precipitate out the alcoholated complex,and drying the precipitate The products may be useful in antiperspirantcompositions and as intermediates in non-aqueous solvents.

8 Claims, No Drawings ALCOHOLATED BASIC ALUMINUM HALIDE COMPOUNDS ANDMETHOD OF MAKING SAME The present invention relates to alcoholated basicaluminum halides and methods of making the same. More particularly, theinvention is directed to a method of producing anhydrous basic aluminumhalide complexes having a substantial portion of free and coordinatedalcohol, and to products produced by this method which may be useful inantiperspirant compositions and as intermediates in non-aqueoussolvents.

Aluminum chlorhydroxide compounds have long been used as an activeingredient in antiperspirant compositions. Furthermore, such compoundsare useful in the preparation of a number of aluminum and aluminumchlorhydroxide derivatives.

However, presently known aluminum chlorhydroxide compounds have not beentotally satisfactory for the above uses due to the presence of free andcoordinated water in the compound. For example, aluminum chlorhydroxidecompositions containing water have been known to form into highlyviscous, gelantinous materials when exposed to non-aqueous alcoholicsolvents. Also, the water present in hydrated aluminum chlorhydroxidehas caused can corrosion in metallic aerosol dispensers, resulting inthe necessity of protective inner can coatings. Furthermore, knownhydrated forms of aluminum chlorhydroxide have been shown to beincompatible with Freon propellants used in aerosol type dispensers,resulting in gelation of the aluminum chlorhydroxide.

A common hydrated aluminum chlorhydroxide (commercially available underthe trademark CHLORHYDROLof Reheis Chemical Company, a division ofArmour Pharmaceutical Company) is produced by adding aluminum metal toaluminum chloride (AlCl or HCl in water solution. Ifthe water ofhydration is removed to yield an anhydrous product, decomposition occursresulting in insoluble products such as Al(OH) and/or A1 If the productis only partially dried to a solid form short of decomposition, thecompound is alcohol insoluble and produces difficulties in somenon-aqueous antiperspirant formulations, necessitating additionaltreatments prior to use. Also, when the compound is used as anintermediate, extreme care is necessary to prevent decomposition.

A previously known aluminum chlorhydroxide complex having a very lowwater content was produced by reacting anhydrous aluminum chloride (Alclalcohol, water, and aluminum metal in the presence of heat. Theresulting product was an aluminum chlorhydroxide-alcoholate of thegeneral formula:

Al, Cl, (0H),, (OR) X H 0 I where n, x, y and z are integers such thatx-l-y+z=3n, R is an alkyl group, and X may be zero to seve'ral weightpercent of the total compound. Although these basic alcoholates wereconsidered for antiperspirant .use, they yielded products which were tooacidic for topical use, and they lack the ionic nature necessary for aneffective antiperspirant. While such an alcoholate derivative ofaluminum chlorhydroxide may be made more ionic through chemicalreaction, the product is not very labile for substitution.

Attempts were also made to use aluminum alkoxides, produced by addingaluminum metal to an alcohol in the presence of a catalyst or by addingaluminum chloride to a sodium alkoxide (NaOR), where R is an alkylgroup. However, these products were found to lack the necessary ionicityfor antiperspirant use. Although the products could be made more ionicby adding aqueous ionic compositions to them, this would reintroduceundesirable water into the products. Also the alkoxides hydrolyzevigorously with water and decompose readily when employed asintermediates.

Accordingly, it is an object of the present invention to produce ananhydrous basic aluminum halide compound which is soluble in andcompatible with both aqueous and non-aqueous media, such as those usedin antiperspirant formulations.

It is a further object of the present invention to produce an anhydrousbasic aluminum halide composition which will not gel in non-aqueoussystems and solvents.

Another object of the present invention is to produce a compound whichwill serve as a chemical intermediate in the formation of usablederivatives of aluminum and aluminum halides without decomposition.

Still another object of the present invention is the production of abasic aluminum halide compound which will not result in can corrosionwhen used in metallic aerosol dispensers.

A still further object of the present invention is to develop a methodof producing an anhydrous basic aluminum halide compound which willsatisfy the above objects.

Other objects will appear hereinafter.

The above objects are achieved by the present invention by forming anon-hydrated alcoholic form of basic aluminum halide in which alcoholmolecules replace substantially all of the free and coordinated watermolecules and become chemically and/or physically bound so as toconstitute an integral portion of the complex basic aluminum halideentity. The nonhydrated, alcoholic form of the basic aluminum halidewill have a water content of less than about 2 percent by weight.

The above objects are further achieved by the process of our inventionwhich involves the reaction of a ketal or dialkoxyalkane, particularlydimethoxypropane or diethoxypropane, in an alcohol solvent with a watermolecule of the hydrated basic aluminum halide. As a result of thisreaction, the ketal is chemically converted into a ketone, which isvolatilized off, and an alcohol. The resulting alcohol and/or thealcohol solvent present in the system then takes over the vacant watersites on the basic aluminum halide -molecule=1and becomes .chemicallyand/or physically bound in some manner to form an anhydrous alcoholatedbasic aluminum halide.

Although the use of one particular ketal (2, 2' dimethoxypropane) as awater-removing agent is known, the use of this and other ketals such as2, 2' diethoxypropane in forming alcoholated basic aluminum halides is,to our knowledge, novel and unexpected.

The hydrated basic aluminum halide compounds used in the formation ofthe products of the present invention are represented by the generalformula:

Al, (OH), A X H O where small n, x, and y are integers such that x+y=3n;X may be from 2 to 4 and need not be an integer; and A may be chlorine,bromine, iodine or mixtures thereof.

Of particular interest for use in the present invention are the highlybasic aluminum halides of the above formula where x=5, y=1 and n=2.Products of the present invention may also be made from glycol complexesand other derivatives of the above basic aluminum halides, as describedmore fully below.

The first step in the process of the present invention is to dissolvethe hydrated basic aluminum halide in alcohol. Virtually any solvent inwhich the hydrated basic aluminum halide is soluble could be used, andethanol and methanol are particularly suitable. However, the use ofsolvents such as the higher molecular weight alcohols, includingpropanol, butanol, secondary butanol and isopropanol, have not exhibitedpromise for the conversion of 5/6 basic aluminum halides due to theinsolubility of the salts in these alcohols. The above mentionedalcohols may, however, be used in the conversion of glycol complexedbasic aluminum halides, as discussed more fully below.

The basic aluminum halide compound is preferably dissolved in thealcohol to the extent of about 30 weight per cent. This solution is, inturn, diluted with additional alcohol so that a volume of at least aboutfive times that of the original solution volume is achieved.

To this solution is added a ketal (also referred to as a dialkoxyalkane)having two methoxide or ethoxide groupings. Of the ketals tried in theprocess of the present invention, 2,2'-dimethoxypropane (DMP) and2,2-diethoxypropane (DEP) are preferred. On the other hand,dimethoxymethane, diethoxymethane and 1,1 '-diethoxyethane have not beenfound to yield satisfactory dehydrated products, although slight watercontent reduction is realized.

The ketal is added to the alcoholic solution to an extent in excess ofthe amount needed to react with all of the water present on the basicaluminum halide compound and to allow for its further reaction withadditional water which may be present in the solution and assuresubstantially complete dehydration of the aluminum compound. It ispreferred that about four mols of ketal be added for each mol of waterpresent on the basic aluminum halide. It is also preferred that theaddition be made with constant agitation of the solution in order toprevent premature precipitation of the alcoholated product.

The resulting solution is heated, preferably with steam at 100 C, tovolatilize the ketone formed and concentrate the solution by evaporationuntil the solution volume is about-one third or less of its originalvolume before heating. The solution is then cooled to about 25 to 30 C.

To the cooled solution is then added an additional excess of the ketalto precipitate the product out of the concentrated solution. Excesses toan extent of about three mols of ketal for each mol of water on thebasic aluminum halide compound are efficient in recovering yields ofgreater than 90 percent. It is also possible to use precipitating agentsother than the dialkoxyalkanes, such as alcohols, ethers, ketones,alkanes, etc. The only essential criteria for the precipitating agentare that the derivative not be soluble in it and that it not contaminatethe derivative.

Finally, the resulting precipitate is dried to produce a solid product.The method of drying the precipitate is important insofar as it isnecessary to minimize water contamination and excessive alcoholvolatilization. Accordingly, it is necessary that there be a minimum ofexposure to atmospheric water and that relatively low dryingtemperatures be used. Preferably, the precipitate is dried under vacuumof one half atmosphere at temperatures below 40C until a free-flowingpowder is obtained having the desired alcohol content. Alcohol contentsof about 10 to 40 percent by weight may be attained, with a range ofabout 20 to 30 percent being preferred. Free and coordinated watercontents of less than 2 percent by weight are also attained.-

Although the precise nature of the chemical reaction involved in themethod of the present invention is not known, the mode of bonding of thealcohol to the basic aluminum halide is expected to be quite complex andnot unlike that of the water bonding to basic aluminum halides.Furthermore, though applicants do not wish to be bound by any particulartheory, it is believed that an intermediate of short life is formedbetween the water and the dehydrating agent, and hence, the replacementof water molecules with alcohol molecules is not expected to proceedstrictly on a one to one basis.

All alcohol and water analyses were performed by employing a Beckmanmodel GC-S Gas Chromatograph which incorporated a thermal conductivitydetector. For methanol, water and ethanol, an 8-foot copper column of0.25 inch O.D. packed with Paropak Q (-100 mesh), with a columntemperature of 150C, detector temperature of 190C, an inlet temperatureof 160C, and a gas flow of 50 mls. of He per minute were employed. Forthe other alcohols, a 6-foot copper column of the same CD. as above wasemployed with Paropak N in the mesh range as previously described. Thecolumn specifications in these cases were as above except the detectortemperature was 200C and the inlet temperature was 210C.

The products and methods of the present invention may be understood morefully with reference to the following specific examples:

EXAMPLE] A 100 gram sample of spray-dried aluminum chlorhydroxide(prepared according to the method described in copending applicationentitled Alcohol Soluble Basic Aluminum Chlorides and Method of MakingSame, filed on even date herewith and assigned to the same assignee asthe present application), assaying approximately 25.0 per cent aluminum,17.0 per cent chloride and 22.0 per cent water, was dissolved in 800grams of methanol. To this solution was added with constant agitation500 grams of DMP. The resulting solution was steam heated, concentratedto about 30 per cent of its original volume, and cooled to about 25 to30C. To the cooled solution was added about 400 grams of additional DMP.The precipitate was collected and dried under a one half atmospherevacuum at temperatures below 40 C. The yield was about to per cent and aproduct analysis showed the product to contain about 20 per centaluminum, 15

per cent chloride, one per cent water, and 30 per cent methanol.

EXAMPLE II A sample of spray-dried aluminum chlorhydroxide was-processedas in Example 1', except that the sample was dissolved in ethanol, andDEP was substituted as the dehydrating and precipitating agent. Asimilar yield and product analysis to that in Example I was obtained,except that the product contained about 30 per cent ethanol instead ofmethanol.

EXAMPLE 111 A 10 gram sample of 5/6 basic aluminum chloride, assaying23.7 per cent Al, 16.2 per cent Cl and 24.4 per cent B 0, was dissolvedin 500 mls. of MeOI-I. To this solution was added 450 mls. of DMP, afterwhich the system was concentrated on a steam bath to a volume of 200mls. and cooled to room temperature. An additional 100 mls. ofDMP wasthen added, and the resulting precipitate was filtered and vacuumdried-to a free flowing product which was found to contain 21.3 per centAl, 13.7 per cent Cl, 0.5 per cent H 0, and 38.5 per cent MeO'H.

EXAMPLE IV A 30 gram sample of a 10 per cent solution of 5/6 basicaluminum bromide in ethanol was diluted with 50 mls. of additionalethanol. To this mixture was added 125 mls. of DMP. The solution wasthen concentrated to 50 mls. volume on a steam bath. After cooling of hesystem, and additional 100 mls. of DMP was added for precipitation ofthe product. The filtered and dried product was found to contain 13.1per cent A1, 15.0 per cent Br, 0.7 per cent H O, 26.1 per cent MeOH and13.2 per cent EtOI-I.

EXAMPLE V A 6 gram sample of .basic aluminum chloride (22.4 per cent A1,15.1 per cent CI, 28.7 per cent 11 was dissolved in 20 grams ofmethanol. Ten grams of the above solution were then diluted with 75 mls.of methanol, and 50 mls. of DMP were added to the diluted solution. Thesystem was then concentrated to 20 mls. on a steam bath and cooled. Theproduct was precipitated by the addition of 50 mls. of DMP, after whichthe product was filtered and dried. The analysis showed the product tocontain 19.6 per cent A1, 13.2 percent Cl, 17.3 per cent MeOH and lessthan 0.1 per cent H O.

EXAMPLE VI A sample of basic aluminum chloride (25.4 per cent A1, 17.2per cent C1, 22.1 per cent 11 0) was processed in the same manner asExample V, except that acetone was used to precipitate the product. Theresulting product was found to contain 19.7 per cent A1, 13.7 per centC], 1.5 per cent H 0 and 29.7 percent MeOI-I.

EXAMPLE VII The product of Example V1, which contained 29.7 per centMeOI-I, was redissolved in ethanol and redried. The resulting newproduct contained 35.5 per cent EtOI-I.

EXAMPLE V111 A 5 gram sample of 5/6 basic aluminum iodide 17.6 percentA1, 42.8 percent 1, and 12.1 percent 11 0) was dissolved in- 200 mls. ofethanol. To this solution was added 200 mls. of DMP. The solution'wasconcentrated to a volume of 100 mls. on a steam bath and then cooled toroom temperature. To this solution an additional 100 mls. of DMP wasadded to cause precipitation. The precipitate was removed from solutionby filtration and dried to a free-flowing powder product. This productwas found to contain 15.1 per cent A1, 32.0 per cent 1, 12.1 per centEtOl-l, 18.4 per cent MeOH, and 2.8 per cent H O.

In addition to the use of the usual hydrated forms of the basic aluminumhalides as the starting material for the process of this invention, thepresent invention also contemplates the conversion of other forms of thebasic aluminum halides, such as the glycol complexed basic aluminumhalides, as illustrated in the following exarnples: I

. EXAMPLE IX A sample of propylene glycol complexed 5/6 basic aluminumchloride (such as that described in U. S. Pat No. 3,420,932, andobtained from the Reheis Chemical Company under the trademark REHYDROL)was dissolved in propanol and DMP was added as the dehydrating agent.The solution was then processed as in Examples I and II above, and theresulting dried product was shown to contain (by weight): 27.2 per centpropanol, 1 1.6 per cent MeOH, 0.8 per cent H 0), and 4.7 per centpropylene glycol.

EXAMPLE X A 2 gram sample of Rehydrol was dissolved in 50 mls. ofethanol, and 50 mls. of DEP were added to the solution. The solution wasthen concentrated on a steam bath to a volume of 25-30 mls. Aftercooling the solution, 25 mls. of DEP was added, and the resultingprecipitate was vacuum filtered and dried. The product analysis showed14.5 per cent A1, 9.8 per cent CI, 0.6 per cent H O, 35.9 per centEtOI-l, and 9.6 per cent propylene glycol.

EXAMPLE XI A 3 gram sample of Rehydrol (20.3 per cent A1, 13.8 per centCl, 6.7 per cent H O, 31.9 per cent propylene glycol) was dissolved in100 mls. of butanol. The Rehydrol solution was then dehydrated with 100mls. of DMP, after which the solution was heated on a steam bath andconcentrated to a volume of 20-25 mls. To the cooled solution was addedmls. of DMP, and the precipitated product was filtered and dried. Thedried product was found to contain 8.9 per cent A1, 6.2 per cent Cl, 0.5per cent 11 0, 3.4 per cent propylene glycol, 8.6 per cent MeOH and 42per cent butanol.

EXAMPLE XII A 10 gram sample of Rehydrol (19.9 per cent A1, 13.8 percent Cl, 30.2 per cent propylene glycol, 8.6 per cent H O) was dissolvedin 450 mls. of methanol. To this solution was then added 500 mls. ofDMP. This system was concentrated on a steam bath to 200 mls.

volume and cooled to room temperature. To the cooled I propylene glycol,1.1 per cent H and 38.2 per cent MeOH.

EXAMPLE XIll An equal weight aliquot of the same Rehydrol batch used inExample X11 was treated identically with the sample in X11 except that500 mls. of ethanol was used as the solvent instead of methanol. Theproduct analysis showed: 16.9 per cent A1, 11.4 per cent C1, 5.0 percent propylene glycol, 0.7 per cent 11,0, 19.6 per cent EtOH and 18.1per cent MeOl-l.

It will be noted from the above examples that the particular alcoholsolvent used in the process of the present invention need not correspondwith the particular dehydrating or precipitating agent used. That is, itis not necessary that methanol be used with DMP and ethanol be used withDEP, as for example in Examples l-lIl and X11. However, where thealcohol and dehydrating agent do not correspond, the resultant productwill tend to contain the alcohols of two different alkane groups, suchas in examples 1V, IX nd XIII.

The products of all of the above examples are alcohol soluble and stablefor substitution and derivative production, such as by incorporating analcohol soluble substance directly into the complex or by replacing thealcohol groupings with other groups. For example, the products may bereacted with stearic acid in an alcohol solution to form a textileimpregnating agent which renders a woven textile fabric waterproof.

Furthermore, the ionic character necessary for effective antiperspirancyand/or astringency is maintained in the above alcoholated species. Forexample, the pH of v a 30 per cent solution of the above products inanhydrous ethanol is about 2.2 to 2.3, which corresponds to a relativepH in water of about 4. Therefore, any of the above products exceptthose containing methanol, which is highly toxic, could be used inantiperspirant compositions.

In addition, the above products show a high degree of compatibility withthe halogenated hydrocarbons which are conventionally used as aerosolpropellants for antiperspirant compositions. For example, the carbontetrachloride compatibility (defined as the number of cubic centimetersof CCl, to effect a permanent cloudiness to 60 grams of a 30 per centsolution of the product in anhydrous ethanol) of the methanolate'd andethanolated products ranged from about 240 to 464 cubic centimeters of'CCl, per standard test sample. These results compare favorably with thevalues of between 150 and 200 cubic centimeters CCl for the propyleneglycol complexed basic aluminum chlorides shown in U. S. Pat. No.3,420,932.

On the interpretation of the foregoing specification and the followingclaims, it is to be understood that the term hydrated refers to thepresence of free and/or coordinated water on the basic aluminum halidecompound, which'water is either chemically bound to or physicallyassociated with basic aluminum halide molecules.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

We claim:

1. A substantially anhydrous basic aluminum halide complex comprising analcoholated basic aluminum halide of the general formula:

A1,,(01-l), A, XROl-l wherein x, y and n are integers such that x+y=3n;ROI-l is at least one alcohol selected from the group consisting ofmethanol, ethanol, propanol, butanol, andv isomers and mixtures thereof;X is a number such that the total amount of free and coordinated alcoholin the complex is about 10 to 40 weight percent of the complex; and A isa halogen selected from the group consisting of chlorine, bromine,iodine and mixtures thereof.

2. A substantially anhydrous basic aluminum halide complex according toclaim 1 wherein the complex also includes a minor proportion of glycolbound to the complex.

3. A substantially anhydrous basic aluminum halide complex according toclaim 1 wherein the free and coordinated alcohol in the complex is about20 to 30 weight per cent of the complex.

4. A method of making a substantially anhydrous a1- coholated basicaluminum halide complex comprising the steps of dissolving an at leastpartially hydrated basic aluminum halide compound in alcohol selectedfrom the group consisting of methanol, ethanol, propanol, butanol, andisomers and mixtures thereof, adding to the solution a dialkoxyalkaneselected from the group consisting of 2,2-dimethoxypropane and2,2-diethoxypropane, heating the solution, concentrating the solution,precipitating out the alcoholated basic aluminum halide complex, anddrying the precipitate.

5. A method according to claim 4 wherein the halide is selected from thegroup consisting of chloride, bromide, iodide and mixtures thereof.

6. A method according to claim 4 wherein the precipitating step iscarried out by adding to the concentrated solution a precipitating agentselected from the group consisting of 2,2'-dimethoxypropane and2,2'-diethoxypropane.

7. A method according to claim 4 wherein the basic aluminum halidecompound is a glycol complex of a basic aluminum chloride.

8. A method according to claim 4 wherein the solution is cooled afterconcentrating.

2. A substantially anhydrous basic aluminum halide complex according toclaim 1 wherein the complex also includes a minor proportion of glycolbound to the complex.
 3. A substantially anhydrous basic aluminum halidecomplex according to claim 1 wherein the free and coordinated alcohol inthe complex is about 20 to 30 weight per cent of the complex.
 4. Amethod of making a substantially anhydrous alcoholated basic aluminumhalide complex comprising the steps of dissolving an at least partiallyhydrated basic aluminum halide compound in alcohol selected from thegroup consisting of methanol, ethanol, propanol, butanol, and isomersand mixtures thereof, adding to the solution a dialkoxyalkane selectedfrom the group consisting of 2,2''-dimethoxypropane and2,2''-diethoxypropane, heating the solution, concentrating the solution,precipitating out the alcoholated basic aluminum halide complex, anddrying the precipitate.
 5. A method according to claim 4 wherein thehalide is selected from the group consisting of chloride, bromide,iodide and mixtures thereof.
 6. A method according to claim 4 whereinthe precipitating step is carried out by adding to the concentratedsolution a precipitating agent selected from the group consisting of2,2''-dimethoxypropane and 2,2''-diethoxypropane.
 7. A method accordingto claim 4 wherein the basic aluminum halide compound is a glycolcomplex of a basic aluminum chloride.
 8. A method according to claim 4wherein the solution is cooled after concentrating.